The invention disclosed herein relates generally to a bottle labeling machine and, in particular, to apparatus for applying a blemish concealing curable liquid coating to the bottles.
Reusable glass or plastic bottles often become unsightly as a result of nicking, scratching, chipping and abrading during repeated recycling in bottling plants as well as in transport to and from the user. Most of the scratches and so forth on the bottles occur in the upper and lower zones of the cylindrical bottle bodies. To make the bottles more attractive, some bottling plants apply a thin film of liquid plastic such as siloxane which covers the scratched and abraded zones and imparts a new appearance to the bottles. German patent specification DE-OS 29 41 105 shows and describes a film application system.
It has been proposed to moisten reusable bottles in the bottling plant with a cold liquid treating agent such as is applied to the bottles in the glassworks. In the bottling plant, the protective film applied by the glass bottle manufacturer is thereby renewed. It is also a known practice to apply a colored film to bottles in the form of a liquid, viscous or pasty plastic substance as a protective coating. In the ensuing description, any liquid, viscous or pasty agent suitable for application to the surface of bottles are encompassed in the word "liquid" in the interest of brevity.
There are in use in industry specialized free-standing machines which are dedicated to applying curable liquid coatings to bottles. The bottles undergoing treatment are transported in a circular path by means of a conventional starwheel and while being translated, are set in rotation by rolling on a curved surface which has frictional properties in conjunction with rolls which turn with the transport starwheel or slide shoes of elastic material which are moistened continuously with the liquid being applied to the bottles. Generally, these specialized machines apply the coating liquid to the bottles before they are labeled which is satisfactory insofar as the application of the liquid is concerned. However, use of these specialized machines is disadvantageous because the machines must necessarily occupy a large amount of space and they are expensive investments.
Some known labeling machines more desirably have a liquid coating application arrangement associated with a turntable and the bottles are acted upon before arriving at the labeling station. An example is given in German patent specification DE-OS 30 08 096. The applicator arrangement in this case is fully integrated into the labeling machine so that no additional space is required in the bottling plant for a specialized machine and the additional investment costs are more moderate. These machines have fewer problems in connection with transporting bottles since, for feeding the bottles into the machine with uniform spacing between them, an infeed worm conveyor is present already and the bottles can be accurately and gently transported by the transport starwheels. The starwheels are conventionally comprised of vertically spaced apart generally circular jointly rotating plates which have pockets equally spaced around their circumference for receiving bottles. Almost invariably, they are associated with centering bells which are lowered to engage the mouth end of the bottles to stabilize them as they are transported on a turntable and which can be raised to release the bottles for discharge at high production rates. Unfavorable characteristics of the known machines is that they can foul up the labeling station and they to some degree impair adhesion of the label as a result of the liquid coating being applied to the bottle shortly before the label is applied. Moreover, a large part of the treatment path on the turntable is used for labeling so that only simple labeling runs can be made or an unusually large and correspondingly expensive labeling machine must be used.